As part of its ongoing strategic "pivot" towards the Pacific, early this year the Defense Department announced it would design a new missile able to quickly cross long distances and penetrate sophisticated air defenses, of the kind rapidly proliferating across Asia. The so-called "conventional prompt strike option" would be submarine-launched, the Pentagon said in its January Defense Budget Priorities and Choices release.

The department placed great emphasis on the new weapon, declaring that "we had to invest in capabilities required to maintain our military's continued freedom of action."

But 11 months later, the Pentagon has yet to take meaningful, practical steps towards developing the prompt strike option, casting into doubt the department's ability to solve the kind of anti-access, area-denial problem posed by, for example, China's fast-modernizing navy and air force.

"The department is investigating the technologies that would be required for a conventional prompt global strike weapon," Lt. Col. Melinda Morgan, a spokesman for the Office of the Secretary of Defense, told AOL Defense. But, she went on, "the department has not made any specific concept decisions at this time."